I used a simple Reflectix insulating foam sheet, 1/4" thick, as the first layer of insulation under the plywood
deck overhead. First I applied one-inch squares of double back tape at convenient spots, then simply pressed the Reflectix in place between the stringers. I did this on a very hot day, so the moment I lifted the Reflectix over my head
and pressed it onto the underside of the deck, the temperature dropped 10-15 degrees. Then, for added benefit, I used the tape on the underside of the Reflectix, then applied a one-half inch layer of the pink Foamular rigid insulation. These are covered with a 1/8" thick, epoxy-coated mahogany plywood/Formica headliner
, held in with screws and finish washers. It is a great insulator combination, easy to wipe clean of galley
grease or any other material.